[T]he vast majority of arrests are not for violent or property crimes: "In 2007, the FBI estimated that 14,209,365 arrests occurred nationwide for all offenses (except traffic violations), of which 597,447 were for violent crimes, and 1,610,088 were for property crimes. That means just 15.54% of arrests were for violent crimes or property offenses, a figure which seems surprisingly low to me.

Some of that can be explained by the drug war: "Law enforcement made more arrests for drug abuse violations (an estimated 1.8 million arrests, or 13.0 percent of the total number of arrests) than for any other offense." What's more, 42.1% of drug arrests were for pot possession.